Reproductive system Part I Lectures 39-40 w2012

Reproductive system Part I Lectures 39-40 w2012 -...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Reproduc)ve System I: Overview of Reproduc)ve System Anatomy and Male reproduc)ve physiology Lectures 39 ­40 Recommended reading: Sherwood 7th edi)on Chapter 20 pp. 741 ­745, 749 ­761 Topics to be covered in these lectures Male reproduc)ve system anatomy Female reproduc)ve system anatomy Gene)c and hormonal control of sex determina)on and differen)a)on The male gonads: testes Spermatogenesis and anatomy of a spermatozoan Roles of male reproduc)ve tracts and accessory glands Male reproduc)ve endocrinology Roles of LH and FSH Effects of testosterone Erec)on and ejacula)on Male Reproduc-ve System •  Includes gonads, reproduc-ve tract, and accessory sex glands •  Role: Make sperm  ­ deliver sperm Side view Fig. 20 ­1, p. 743 Front view Female Reproduc-ve Func-ons •  Func-ons –  Produc-on of ova (oogenesis) –  Recep-on of sperm –  Transport of sperm and ovum to common site for union (fer-liza-on or concep-on) –  Maintenance of the developing fetus un-l it can survive in outside world (gesta-on or pregnancy) •  Forma-on of placenta (exchange organ between mother and fetus) –  Giving birth to the baby (parturi-on) –  Nourishing infant aIer birth by milk produc-on (lacta-on) Female Reproduc-ve Organs Fig. 20-2, p. 744 Sexual differentiation of mammalian gonads and reproductive tracts Mouse: begins embryonic day 10.5 (gestation ~19 days) Human: begins at 10 weeks (gestation 38 weeks) Mammals have genotypic sex determination: Inheritance of the Sry gene on the Y chromosome XX + XY Sry transgene [ SRY External genitalia Y chromosome AMH: Anti-Mullerian Hormone DHT: Dihydrotestosterone + scrotum, descent of testes Male Reproduc-ve System: Testes Perform dual func-on: •  Produce sperm (at puberty) within seminiferous tubules •  Secrete testosterone from Leydig cells (during development and then again at puberty) Descent into scrotum provides cooler environment essen-al for spermatogenesis Credit: © Dr. Richard Kessel & Dr. Gene Shih/Visuals Unlimited Seminiferous tubule filled with sperm. SEM X335. Fig. 20 ­7a and b, p. 750 Male Reproduc-ve System Spermatogenesis Haploid Direc-on of sperm matura-on Meiosis Mitosis Diploid Fig. 20 ­7d, p. 750 Male Reproduc-ve System Spermatogenesis: Anatomy of a Spermatozoan Figure 20 ­9 p. 754 Male Reproduc-ve System Spermatogenesis: 180 X106 sperm/ejaculate (below 20 X 106 infer-le) •  Epididymis and ductus deferens  ­Store and concentrate sperm  ­Increase sperm mo-lity and fer-lity prior to ejacula-on •  During ejacula)on: sperm are mixed with secre)ons released by accessory glands 1. Seminal vesicles: supply fructose and prostaglandins Provide more than half the semen 2.  Prostate gland: alkaline fluid that neutralizes acidic vaginal secre-ons 3. Bulbourethral glands: Mucus Male reproduc-ve endocrinology Note: Adequate sperm produc-on depends on local estradiol produc-on! Pep-de hormone Steroid hormone Fig. 20 ­10, p. 755 Male reproduc-ve endocrinology: effects of testosterone (via conversion to estradiol!) Table 20-1, p. 751 Male reproduc-ve physiology: erec-on reflex and ejacula-on Fig. 20 ­12, p. 761 Nitric oxide mediated! Viagra etc. inhibit cGMP turnover Table 20 ­4, p. 759 ...
View Full Document

This note was uploaded on 04/05/2012 for the course NPB NPB101 taught by Professor Weidner during the Spring '08 term at UC Davis.

Ask a homework question - tutors are online